A data transmission standard (e.g., USB) is an industrial data bus standard used to transmit digital data between electronic devices. A transmission speed of the USB 3.1 type that is being currently used is ten times faster than that of the USB 2.0 type, and the USB 3.1 type is used to transmit high-definition content. According to various embodiments, in the case of the USB 3.1 type, the role of an external device, which is connected to each plug, for example, a USB host or a USB device may be relatively determined.
A specific current is periodically applied to an identification contact (e.g., a CC1 contact or a CC2 contact) to define the role of the external device connected to each plug of the USB 3.1 type. In this case, when a foreign object (e.g., moisture) flows into a plug, electrolytic corrosion may occur at the identification contact.